Post #14290

Why don't animals get infected with human diseases and vice versa? You all know these people who shout at every step: “Ugh, don’t touch this dog, she has a lot of viruses!” So, after reading this article, you can answer them quickly, clearly and reasonably. A dog may have viruses, but a person won’t get sick from them even if they hug him 24/7. And vice versa also works: an owner with ARVI is not at all dangerous to his pets. This is because this system is much more complex and interesting than it seems. But first, let's figure out what this “virus” even is? Many people imagine it as a tiny and very evil parasite that just wants to infect someone as quickly as possible. However, this is fundamentally wrong. A virus is not even a living creature in the usual sense. He has no body and metabolism, he does not know how to move and eat independently. It's just a flash drive with a piece of genetic information that uses the cells of other living beings for its own reproduction. Then a logical question arises: if the virus is so simple and almost not alive, why would it infect anyone at all? No reason. Viruses don't need anything at all. They are not interested in our quarantines, masks and QR codes at the entrances to restaurants. They don’t make us sick on purpose because they are so bad. This chthon does not even search for a person or dog purposefully: it enters someone’s body completely by accident: with microdrops of water, dust or secretions of the patient. But then the most interesting part begins, and this will be the answer to the question of the entire article, why dogs don’t get our viral diseases, and we don’t get theirs. When the virus enters the body, at first it simply floats in biological fluids. It does not have any flagella or cilia to swim somewhere. There are also no sensory organs that would tell influenza viruses to go to the nasopharynx, and intestinal viruses to the gastrointestinal tract. This infection simply tries to penetrate ANY cell that comes in its way! All cells in our body have a membrane on which receptors are located. With their help, cells communicate with each other, receive nutrition and remove metabolic products. These doors are locked so that nothing unnecessary gets in or gets out. Viruses also have receptors - they poke them into all cells in a row - for good luck. Sometimes they get lucky, and the receptor key on the virus matches the receptor door on the cell. If this happens, the cell itself drags the virus inside, assuming that if there is a match in receptors, then this is definitely something needed. Having climbed into the cell of the host organism, the virus slips its fragment of genetic information into it as instructions for action. Instead of minding her own business, she endlessly spends her resources on creating new copies of the virus that has entered her. Over time, they leave the cell, enter the body again, and the cycle repeats. That is, the virus does not even reproduce i